Platypus Day
by The Nerdinator
Summary: The Continuing Adventures of Phineas and Ferb, S1E3. The gang celebrates a platypus-themed holiday, which Doofenshmirtz is desperate to ruin. Perry is forced to confront his dark past when he learns his estranged brother has teamed up with the evil scientist - but can a female platypus help him out? AU where the last four episodes of the series never happened.
1. CAPAF theme song

**Somewhere, in an alternate universe...**

 _There are seventy-five days to summer vacation,_

 _Before school comes along just to end it._

 _So the annual problem for each generation_

 _Is finding the best way to spend it._

 _Like maybe:_

 _Crossing a tundra, giving tours on a rollercoaster,_

 _or skiing down a mountain of beans._

 _Creating a system for remembering everything,_

 _Or synchronizing submarines._

 _Meeting ghost patriots, taming tiger sharks,_

 _Or making a self-driving car._

 _Cleaning a time machine, stretching a rubber tree,_

 _Or whaling away on guitars!_

 _As you can see, there's a whole lot of stuff to do,_

 _Before the new grade this fall._

Phineas: C'mon Perry!

 _So stick with us, 'cause Phineas and Ferb are gonna do it aaaaaaaaaaaaaall!_

 _And with Susanna's help, Phineas and Ferb are gonna do it aaaaaaaaaaaaaall!_

Candace: Mo-om! Phineas and Ferb are making a spinoff!

Susanna: Seriously, Candace?


	2. Where's Perry?

**AN: This fic is set on June 18, 2013.**

* * *

The blue flash touched down in the yard and dissipated.

"Hey guys," Susanna said. "Whatcha doin' with that getup?"

She had asked this because everyone was wearing teal-and-orange versions of their normal clothing.

"It's Platypus Day, kiddo," Phineas said. "A holiday dedicated to our duck-billed, semi-aquatic friends."

"Oh...right. Sorry, I haven't celebrated that since I was four."

"Why not? It's a great holiday."

"Platypus Day doesn't _exist_ anymore. The International Council of Serious People deemed it unneeded, as platypi aren't endangered anymore by my time."

* * *

 **June 18, 2041  
**

"Why does this exist?" one member of the ICOSP asked.

"Because if it didn't, we would end up in World War 4," another responded.

* * *

 **June 18, 2013  
**

"Well, that was weird," Lizzy said.

Silence.

"Susanna, it's a real shame. Platypus Day is one of the best holidays. Hey Ferb! I know what else we're doing today."

"Helping my niece reconnect with a disestablished celebratory event?" he asked.

"Yes. Yes, we are. How did you know that?"

"I have my ways."

Susanna looked at the reader, confused.

"Anyway, we're going to start with the star of the day...Perry!"

Phineas looked around. "Where is he?"

* * *

Perry looked around. No one nearby. Perfect. He jumped inside a platypus-shaped piñata, and slid down into his lair.

* * *

"Happy Platypus Day, Agent P!" Major Monogram exclaimed. He was wearing a platypus hat. "I know you must be anxious to celebrate."

Perry nodded enthusiastically.

"Well, I'm sorry, but knowing Doofenshmirtz, he's probably intent on ruining it, what with you being his nemesis and all that."

Perry understood.

"So get out there and stop him. Oh, and here's some complimentary crayfish for you - we know that's part of your natural diet."

A plate, laden with live crayfish, appeared from inside his desk. Perry took the plate in his hands and ate. Once he was done, he left.

 _Pe-rry is an aquatic predator!_


	3. Platypusing Intensifies

"So if Perry is not here...now what?" Baljeet asked.

"I guess we'll have to celebrate without him," Phineas responded. "It's a shame, but then again, it _is_ his day. We should let him do what he wants to do."

"But what are we going to do?"

"Platypus theme park."

"Well, it's not much, but at least it's something," Susanna said. She had changed her t-shirt to a teal one with a platypus face on it, and her hair bow was now teal as well.

"Yes. Yes it is," Phineas said.

(Quirky Worky song as they build a platypus-themed amusement park).

* * *

Perry arrived at Dr. Doofenshmirtz's lair. He was immediately snared in a teal-colored towel and draped on a railing.

"Hello, Perry the towel-pus," said Doofenshmirtz. "See what I did there? It's funny 'cuz...you're in a towel...man, I have got to stop explaining my jokes."

"Oh NOW you figure it out," Perry said.

Doofenshmirtz, being human, only heard "Gngngngng."

"Well, I guess you don't have to figure out my scheme," Doofenshmirtz replied. "But I'll tell you anyway, because every villain does that."

He continued. "You see, Perry the platypus, you are my nemesis. So any holiday dedicated to your species really irks me, right?"

"One would think so."

"But now I can make it so I can enjoy it, but nobody else can. BEHOLD! The Party-Poop-inator!" he exclaimed, pointing to a teal inator shaped like a giant party hat.

"Now, let me clarify, it does not clean up poop. That is disgusting and unclean. What it does is it makes things not be fun anymore. Platypus Day will be ruined!"

"I'm going to stop you, Doof. Just like I've always done."

"Oh, you aren't going to stop him, Percival," came a new voice.

Perry turned to see a platypus that looked a lot like him, but with blue eyes and no hat. Near him was a female, realistically colored platypus.

"I made a friend!" Doofenshmirtz said. "Harry the platypus. At first I thought, why would a platypus want to help me ruin Platypus Day? But then it turned out he doesn't like you either, so that makes him a GREAT ally!"

There was a beeping noise.

"It's muffin time, sir," Norm called from the lair's kitchen.

Doofenshmirtz smiled. "Wait here, guys. The muffins beckon."

He left.

Perry swallowed hard as Harry grinned evilly.

"Welcome to the party," he said, "brother."

* * *

 **AN: Bet you didn't know Perry could speak. Or had a brother who was evil.**

 **Platypus dialogue will be underlined.**


	4. Perry's Past

"Phineas and Ferb made a theme park? Oh, they are SO busted!" Candace exclaimed when she saw what was in her backyard.

"It's Platypus Day," Stacy, who was currently next to her, replied. "This is obviously how they're celebrating it. How are _you_ going to celebrate it?"

Candace thought, then said sarcastically, "I think I'll jump in a lake or something."

"Good, good, you're taking baby steps. Or should I say, platypette steps."

* * *

Perry, still stuck in the towel, watched in horror as Harry helped Doofenshmirtz with a few final adjustments to the Party-poop-inator.

"You know, sometimes I don't understand why I ever decided to live with him," the realistically-colored platypus said to him.

"How did that come about, anyway?"

"Well, I was born in captivity at the San Francisco Zoo. Until I was kidnapped by some poachers, that is. Then I escaped, and when I found myself in Danville, Harry took me in. But in return for his hospitality, I have to help him with his evil schemes."

Perry sighed. "That's my brother alright. Always causing mischief."

"You know, in all the time I spent with him, he never told me he had a brother who was still alive."

"I'm pretty sure he thought I was dead until he met Heinz."

",,,Why?"

Perry looked away. "I don't want to talk about it."  


"You can't avoid your past forever, you know."

"...Okay, _fine_."

Perry took a deep breath. "I was the little egg, and he was the big egg. Now, of the teal, boxy platypus subspecies (which you are not a member of), strength is highly valued. Scrawny ones like me were always getting picked on. I had to teach myself to be smart if I wanted to survive. I saw one of my uncles die after being stabbed by another guy's leg spurs; that day I vowed to never use my own on anyone."  


"Not even the dopey human? He's big enough so that the pain will just be an annoyance to him."

"Doofenshmirtz...he's an odd one. I have to be careful around him or else I'll end up his friend."

They both laughed.

"So, anyway, my brother was picking on me as usual when some poachers came. Mom and Dad fought to protect me, but they were killed. I saw it with my own eyes. My brother did nothing to help me."

"Then you got thrown on a boat and taken here?"

"Well...not exactly. The ship I was on was capsized during a storm. I would've died had it not been for the OWCA finding me, a traumatized little platypette all alone in the middle of the ocean. They took me in, cleaned me up, then put me up for adoption so I could become a secret agent and fight evil humans like the ones who took me and killed my parents, while also finding a new family. The rest is history."

The female platypus brushed one of her bangs out of her face. "That's so sad," she said.

"I know. That's why I don't kid around much. I've been through too much pain."

Doofenshmirtz walked in with a muffin. "Here you go, Perry the platypus. I know it's not much, but I don't want you to starve, even if you are my nemesis. Uh...brown one...you're going to have to feed it to him."

He left, revealing Harry behind him.

"This is low, even for you, Mattie," Harry growled.

"He can't starve, you know."

"Oh, he can starve. I've made sure of that back when he and I were barely hatched."

Mattie sighed and simply stuffed the muffin into Perry's mouth.


	5. A Platypus Theme Park

_Only five mammal species  
_

 _Hatch_

 _From eggs_

 _Four types of_

 _Echidna_

 _With their clawed little legs_

 _But the platypus_

 _Number five_

 _Is the coolest_

 _Monotreme alive_

 _Venomous leg spurs! (just for guys)_

 _Sorta sweating milk! (just for gals)_

 _Look into their differently-pointing eyes_

 _And you'll find your lifelong pal!_

 _Platypus!_

 _Platypus!_

 _We make a fuss for platypus!_

 _Platypus!_

 _Platypus!_

 _We make a fuss for platypus!_

 _They're semi-aquatic,_

 _Insectivorous,_

 _Nocturnal (unless they're the boxy types!)_

 _And you gotta admit, that's pretty cool_

 _For a mammal who reproduces old-school_

 _(Live-birth is not for them)_

 _Platypus!_

 _Platypus!_

 _We make a fuss for platypus!_

 _Platypus!_

 _Platypus!_

 _We make a fuss for platypus!_

* * *

The theme park was like a platypus-themed Six Flags (though I've never been there).

Having seen all there was to see, Susanna said, "I'm starting to get the hang of this."

"That's great!" Phineas exclaimed.

"I have the urge to feed Perry Jr. now. Should have seen that coming."

"Perry...junior? Perry laid an egg?! That's so exciting! Hey Ferb, Perry's going to lay an egg!"

"No, Dad, he isn't," Susanna groaned.

Phineas turned around. "The name 'Perry Jr.' implies Perry had children," he replied.

"I know, and Perry Jr. really is his son. But Perry didn't lay the egg! He's MALE! Male animals don't lay eggs! They just fertilize them!"

"Oh...right," Phineas said. "I feel really stupid. That's such a dumb mistake."

"It's also easy to make," Isabella said, trying to comfort him. "But this implies that Perry found love. That's pretty great." To her daughter, Isabella asked, "Who's the mother?"

"I think she was owned by your friend Lizzie."

Lizzie was confused. "I don't have a platypus."

"You will. Just wait."

Phineas sighed. "I'm tired. Building an entire theme park was exhausting. Say, Ferb, have you got any of that teal cotton candy left? I need some sugar in my system."

Ferb pulled out one from nowhere.

* * *

Perry finally wriggled out of the towel. "Doofenshmirtz, you're going down."

Doofenshmirtz turned around. "Oh, not again. Okay, Perry the Platypus, I don't have all Platypus Day to fight you, you know. Can we do this quickly?"

"Move aside, human," Harry said. He rolled up Doofenshmirtz's left pants leg and shoved his right spur into the scientist's ankle.

Doofenshmirtz howled in pain. "YEOW! I guess that's why you have venom!" He fell over.

Perry gulped. His brother was always stronger than he was. He couldn't take him on in a fight.

But he didn't have to.

Mattie jumped in front of Perry. "Harry, no. You won't hurt him."

"What? Do you know what you're doing?!"

"Yes, I do. I'm leaving you behind, Harry. It's time I started a new life."

"By protecting that worthless piece of fuzz?"

"He's not worthless! He's smart. He's got his morals in the right place. Can't you see that?"

Their argument gave Perry enough time to push the self-destruct button on the Party-Poop-inator. It exploded, sending out a beam of blue light.

"Let's go!" Perry said. He grabbed Mattie's paw, and together they jumped onto a hang glider and flew away.

"CURSE YOU PERRY AND MATTIE THE PLATYPI...platypuses...WHATEVER'S THE PLURAL!" Doofenshmirtz yelled. To Harry he said, "Get out."

Harry obliged.

* * *

While on the hang glider, Perry looked at Mattie.

"Thank you," he said.

Mattie smiled, but found herself blushing, and she wasn't sure why...


	6. New Pet

**AN: Sorry I haven't updated this in a while! The characters have been busy, and I have been busy, so let's finish up this fanfiction!**

* * *

The beam of blue light hit the platypus theme park, bathing it, then dissipating before any of the gang noticed.

"Phoo!" Phineas sighed. "I'm exhausted. Building this thing took a lot out of me, and all the rest of us too."

"You got that right," Buford said, collapsing on the ground.

Susanna somehow hadn't been affected by the beam, but she had still gotten bored. "Yeah, I'm done. Platypus Day _was_ great, though. Thanks for showing me, Dad."

Phineas looked at his daughter and smiled. Then his expression changed. "Now how are we going to remove this theme park from the backyard?"

"Hey kids!" someone from the street called. Phineas and Susanna turned their heads to see a man with a truck labelled "BOB'S AMUSEMENT PARK EMPORIUM".

"I saw your platypus theme park, and I think it would fetch a high price on the market! So, whaddya say, kids - ready to part with it?"

"Yes. Yes, we are," Phineas said.

"Great! I'll take it now." A massive hand came from the back of the truck, scooped up the platypus theme park, and drove away.

"I am confused. How did someone get a warrant for a truck with a hand?" Baljeet asked.

"The same reason why people can get arrested for selling triangles painted to look like pyramids," Lizzie replied. "Seriously, how do laws that stupid even _pass_?"

"That is a very good question."

Perry and Mattie, unbeknowst to them, dropped into the backyard. "Well, this is goodbye, I guess," Mattie said.

"What makes you say that?" Perry asked.

"I have no home. Looks like it's back to the life of a stray for me," she replied sadly.

Perry could not let that happen. She had stood up to his brother - HIS BROTHER - and had helped him realize his brother wasn't worth worrying about anymore.

He had to return the favor.

So he shouted a loud "PHINEAS! FERB!"

But all they heard was a loud "GNGNGNGNG!" Everyone turned and saw the brown platypus by his side.

"Oh, there you are, Perry! And...you made a friend! That's so cool!" Phineas exclaimed.

Mattie was a bit confused, but then she saw Lizzie, and carefully waddled towards her. Lizzie reached her hand down and brought it to Mattie's face. Mattie sniffed the human's hand, before letting her touch her forehead.

Lizzie went into cuteness overload mode. "Ohmygosh! Suz, you were right! This must be the platypus you were talking about! She's so _cute_!"

"But are you ready to handle a platypus?" Susanna asked.

"I have a five-year-old sister. Compared to that, a platypus is nothing." To the platypus, Lizzie asked, "How do you like the name 'Mattie'?"

Mattie smiled. She'd found a home.

She looked at Perry.

She'd found love.


	7. Credits

Doofenshmirtz had bandaged his leg and was now icing it.

"Wow," Vanessa said. "What happened to you?"

"A platypus I thought was my ally rebelled and did this to me," Doofenshmirtz groaned.

"Perry's evil? Since when?"

"No, no, someone else. Harry the platypus."

"What relation does he have to Perry?"

"He doesn't like him. I always wondered if they were brothers, but I don't speak platypus, so..."

The end.


End file.
